The present invention relates to the art of generators and, more particularly, to a device that guides ventilation gas about a stator flange portion of a generator.
During the process of producing electricity, power generators also create heat that must be dissipated away from the generator. Many known generators use fluid cooling to dissipate this heat. In many known generators, the fluid is a gas. Known gas-cooled generators are cooled by ventilated cooling systems that circulate a cooling gas through ducts provided in various components such as a rotor and a stator core.
In some known gas-cooled generators, the stator core is constructed by stacking many layers of magnetic laminations, also known as stator punchings. The laminations are held together by a stator flange positioned on opposing ends of the stator core. Ventilating ducts are defined between the stacked layers of magnetic laminations by providing spacers or inside spacing blocks in the core stack. The passages allow cooling gas to pass through the stator core. The spacers are positioned in such a way so as to ensure tightness of the stator core during assembly and operation, and to avoid blocking or restricting the flow of cooling gas through the stator core. Outside spacing blocks are located at the end portions of the stator core and define a passage or ventilation duct which allows the cooling gas to flow between the stacked laminations and stator flange.
During operation, the stator flange(s) is exposed to heat generated as a result of electromagnetic fluxes flowing from an end winding and axial fluxes from the stator core. Material considerations limit the maximum temperature to which the stator flange can be exposed. If proper cooling is not provided at the stator flange, adjacent insulation may fail and cause a malfunction of the generator. Thus, flange cooling may be required so that heat generated on the flange can be dissipated in a cooling medium.